I think something like this might do what you're looking for
I haven't tested it so I have no idea if it will actually work
DEF TOBIN$(C$)
OUT$=""
FOR I=0 TO LEN(C$)-1
OUT$=OUT$+BIN$(ASC(C$[I]))
NEXT
RETURN OUT$
END
PRINT TOBIN$("HELLO WORLD")
2そうだね プレイ済み